Finish a thread when condition is produced. C/C++ - c++

Question

I have a C code that checks if the left buttom of the mouse has been pressed. It works fine but I don't know how to unhook and exit the current thread after calling the final() function.
This is the code:
LRESULT CALLBACK mouseProc(int nCode, WPARAM wParam, LPARAM lParam)
{
static int count = 0;
static int finalNum;
if (count==0){
//////Generate random number
srand(time(NULL)); // Seed the time
finalNum = rand() % (150 - 50) + 50; // Generate the number, assign to variable.
////////////////////////////////////////////////////////////////////////////
}
//int count = 0;
MOUSEHOOKSTRUCT * pMouseStruct = (MOUSEHOOKSTRUCT *)lParam;
if (pMouseStruct != NULL){
if (wParam == WM_LBUTTONDOWN)
{
count++;
printf("%d",count);
if (count==finalNum){ // user clicked random times the mouse so we launch the final function
printf("\ndone!\n");
final();
}
printf("clicked");
}
printf("Mouse position X = %d Mouse Position Y = %d\n", pMouseStruct->pt.x, pMouseStruct->pt.y);
}
return CallNextHookEx(hMouseHook, nCode, wParam, lParam);
}
DWORD WINAPI MyMouseLogger(LPVOID lpParm)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
// here I put WH_MOUSE instead of WH_MOUSE_LL
hMouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, NULL);
MSG message;
while (GetMessage(&message, NULL, 0, 0)) {
TranslateMessage(&message);
DispatchMessage(&message);
}
UnhookWindowsHookEx(hMouseHook);
return 0;
}
void custom_delay(){
}
int main(int argc, char *argv[])
{
int count = 0;
HANDLE hThread;
DWORD dwThread;
//////Generate random number to call a function after rand() number of clicks
srand(time(NULL)); // Seed the time
int finalNum = rand() % (150 - 50) + 50; // Generate the number, assign to variable.
////////////////////////////////////////////////////////////////////////////
printf("%d", finalNum);
hThread = CreateThread(NULL, NULL, (LPTHREAD_START_ROUTINE)MyMouseLogger, (LPVOID)argv[0], NULL, &dwThread);
if (hThread)
return WaitForSingleObject(hThread, INFINITE);
else
return 1;
}
printf("Keep going");
}
I've tried with ExitThread(0); but it closes all the threads and not only the MyMouseLogger process to print "Keep going".
How should I do it?
thank you for your help!

Answer 1

You can use PostThreadMessage to send a WM_QUIT to the thread, which will cause its message loop to exit.

Answer 2

This isn't really related to hooks as such; you are rather just asking how to safely stop a thread from running.
ExitThread() is never a good choice. So implement your own way to safely stop the thread. In this case, it can be done by for example creating an event through CreateEvent() before creating the thread. Then have your thread check for this event each time in the loop:
while (WaitForSingleObject(hevent_stopthread, 0) != WAIT_OBJECT_0 &&)
GetMessage(&message, NULL, 0, 0))
where hevent_stopthread it the HANDLE to your custom event.
Then simply set this event from the final() function. Your main() function will wait until the thread has finished by its own, by returning 0. Once that happens, you can clean up the event with a call to CloseHandle().